In a portable computer, a main body and a screen are typically coupled with a hinge. A hinge provides an axle along which a screen may open up away from a main body or close down toward the main body. FIG. 1 illustrates a conventional hinge 10 formed with two parts: a screen fastener 30 and a main body fastener 50. The screen fastener 30 includes a first connection plate 32 at one end, which defines two threaded holes 35 therethrough. The first connection plate 32 is fastened to a display using two screws (not shown). The other end of the screen fastener 30 includes a first cylindrical portion 36 defining a cavity 38 therethrough. The main body fastener 50 includes a boss 60, a second cylindrical portion 70, and a second connection plate 80. The second connection plate 80 defines two threaded holes 85 therethrough, and may be fastened to a main body using two screws (not shown). The external diameter of the boss 60 matches the internal diameter of the cavity 38 defined through the screen fastener 30, so that when the boss 60 is inserted in the cavity 38, the boss 60 and the cavity 38 form a "tight fit". Due to this "tight fit", the screen fastener 30 and the main body fastener 50 are not easily separated and, yet, may axially rotate with respect to each other. To assemble a main body and a screen together, either fastener of the hinge 10 is fastened to one of the main body or the display without a covering, using screws. Then the covering is placed over either the main body or the display, to which the fastener has been just secured. Thereafter, the other fastener of the hinge 10 is fastened to the other of either the main body or the display without a covering, using screws. Finally, the covering is placed on the other of either the main body or the display, to complete the assembling process. When a screen and a main body need to be separated for checking or maintenance purposes, one must typically open up the screen, undo the screen covering, and unfasten the screws. Such dismantling process is cumbersome and tedious. Further, since a covering needs to be removed to unfasten screws, the process involves a risk of damaging exposed electrical circuit boards or other internal structures.